package com.carkeeper.web.filter;

import com.carkeeper.service.AuthService;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

/**
 * 网关授权过滤器
 */
@Component
public class AuthorizeFilter implements GlobalFilter, Ordered {

    public static final String LOGIN_URL = "http://localhost:8001/api/oauth/toLogin";

    @Autowired
    private AuthService authService;

    /**
     * 1）判断当前请求是否为登录请求，是的话，则放行
     2) 判断cookie中是否存在信息, 没有的话，拒绝访问
     3）判断redis中令牌是否存在，没有的话，拒绝访问
     * @param exchange
     * @param chain
     * @return
     */
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1.判断当前请求是否为登录请求
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        //2.判断请求路径中是否包含登录请求
        //请求登录和正在去登录的过程是要放行的，不用拦截
        String path = request.getURI().getPath();
        //当是登录请求或者不包含被保护的资源的时候可以访问
        if (path.contains("/api/oauth/login")||path.contains("/api/oauth/toLogin")||!UrlFilter.hasAuthorize(path)) {
            return chain.filter(exchange);
        }
        //3.否则，判断cookie中是否存在信息，没有的话，拒绝访问
        String jti = authService.getJtiFromCookie(request);
        if (StringUtils.isEmpty(jti)) {
        //没有则拒绝访问
            //response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return this.toLoginPage(LOGIN_URL + "?FROM=" + path, exchange);
        }
        //4.判断redis中令牌是否存在，没有的话，拒绝访问
        String token = authService.getTokenFromRedis(jti);
        if (StringUtils.isEmpty(token)) {
            //response.setStatusCode(HttpStatus.UNAUTHORIZED);
            //return response.setComplete();
            return this.toLoginPage(LOGIN_URL + "?FROM=" + path, exchange);
        }
        //5.校验通过，请求头增强，放行
        request.mutate().header("Authorization", "Bearer " + token);
        return chain.filter(exchange);
    }

    //跳转登录页面
    private Mono<Void> toLoginPage(String loginUrl, ServerWebExchange exchange) {
        ServerHttpResponse response = exchange.getResponse();
        //重定向（看见其他）
        response.setStatusCode(HttpStatus.SEE_OTHER);
        response.getHeaders().set("Location", loginUrl);
        return response.setComplete();
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
